This invention is in the field of support grids for spacing and holding nuclear fuel rods in a nuclear fuel assembly.
It is necessary that elongated fuel rods employed in nuclear fuel assemblies be held against undue vibration or lateral movement and that the holding means do not interfere with flow of coolant water along the rods. Many devices have been proposed, including grids formed of strip metal arranged in crossed relationship having fixed stops and spring fingers to engage and hold the fuel rods. Such devices, however, have been formed of relatively heavy gauge metal since rigidity is essential to properly hold the rods in predetermined position. The materials of which the grids are made is expensive and thus the heavy gauge metals employed render the cost of manufacture and maintenance quite high and also unduly absorb neutrons.
It has further been proposed heretofore to incorporate separate vanes adjacent or on the grids to direct coolant flow in an effort to enhance mixing the coolant as it flows through the reactor core.